(US4869755-A)      Photovoltaic element, e.g. solar cell or solar cell module, is encapsulated by two transparent protective films, the inner film being a dielectric Si cpd., the outer film amorphous or crystalline C, combined film thickness being less than 15mn. Pref. inner film is less than 5mn. thick and outer film is less than 1mn. thick. The Si cpd. is formed by plasma or ' microwave-assisted deposition at 500 deg . C max. from the gas phase, producing a Si nitride or Si oxynitride film. Amorphous C film is formed over the Si cpd. at a max. temp. of 200 deg. C.    ADVANTAGE -   High resistance to mechanical and chemical influences.    (DE3725338-C)      Encapsulation for a photo-voltaic element, e.g. a solar cell or a solar cell module, has transparent protective layer over the outer surfaces, which comprises dielectric silicon cpd.The outer surface of the element has two layers covering it. One layer comprises a carbon material while the other comprises dielectric layer.    ADVANTAGE -   Encapsulation is chemically and mechanically resistant and has good optical mechanical and thermal characteristics. (5pp)r    (DE3875299-G)      The cell (10) or solar-cell module is encapsulated by deposition on at least its outside surface of 2 superimposed layers (12,14). These consist respectively of a dielectric Si-cpd and a Carbon-layer, amorphous or crystalline. At least one of the layers is less than 10 micron thick, the sum of both layers is pref. less than 15 micron. The Si-cpd. used is pref. Si-nitride, the thickness of this layer pref. less than 5 micron,or Si-oxynitride, the C-layer is pref. less than 1 micron thick.    The encapsulation is carried out by plasma- or microwave-enhanced chemical vapour deposition (CVD) of the Si-cpd layer at a max. of 500 deg.C and of the C-layer at max. 200 deg.C. substrate-temp.    USE/ADVANTAGE -   The layers provide excellent protection against weathering, without degrading optical, mechanical and thermal properties significantly. The process used allows economic mfr. to be carried out.